Recently, two-way switching power control circuits are installed in electric vehicles, hybrid vehicles, and the like in order to charge electric power generated by photovoltaic power generation and supply charged electric power to households, or the like as needed.
There exists a switching power supply device for performing a two-way power interchange. In the switching power supply device, a full bridge circuit is connected to a primary side of a transformer while a push-pull circuit is connected to a secondary side thereof. The full bridge circuit may perform a switching operation using a phase shift signal.
Further, an isolated DC/DC converter is used. The isolated DC/DC converter is configured such that an operation (or control) of a switching element is switched between a full bridge and a half bridge by a microcomputer. Also, the switching element constituting the full bridge and the half bridge is connected to a primary winding side of a transformer. Thus, switching of the full bridge and the half bridge may be performed by the primary winding side of the transformer. That is to say, in the isolated DC/DC converter, a driving scheme of a secondary winding side of the transformer may not be switched.
In addition, a compact, highly efficient DC/DC converter is also used. In such a converter, a plurality of control schemes such as a full bridge two-way isolated DC/DC converter, a flyback converter, a series converter using a polarity reversing chopper, and a one-way isolated DC/DC converter may be available.